You are correct that you do indeed have +40% Action Skill Cooldown Rate (ASCR), however, keep in mind that +100% ASCR would not result in no cooldown, rather, it would half the cooldown. The idea is that your Action Skill has a base rate at which it cools down, and that rate results in the base cooldown time. Increasing the rate by a given % does not have a linear relationship with how many seconds off the cooldown time you end up getting due to your increased cooldown rate. The equation for cooldown time is of the form:
Where T is the actual cooldown time, B is the base cooldown time, and R is the cumulative bonus to Action Skill Cooldown Rate. The number of seconds off, then, is the difference of B-T.